I have a 1979 Yamaha XS750S which I have recently purchased, I have changed the oil , and filter. Put high octane gas 92 in the bike and now I noticed when I get up to 5000 RPM and over which is way before redline the bike starts to sputter and choke, As if its not getting fuel it begins to cut out. I am wondering what areas to address first and if there are any veteran mechanics on this site please advise me as I can not afford to send it off to the shop they will rape me in hourly wages to do any sort of mechanical repairs !

Any and all advice would be greatly appreciated.

Dave

try a bit of choke and see if it helps. Its not really a choke but an enrichment device so your adding fuel.#

could be that the carbs need cleaning as with all old bikes

Thanks Drew I am going to try it asap. I did spray carb cleaner in the carbs when I first got the bike while it was running and I added seafoam , TO help clean out the lines and carbs as well ! I will get back and let you know what this choke while reaching 5k and over and how it reacts ! Good place to start !